The prior art is replete with light assemblies specifically designed for particular lighting needs and specialized applications. For example, light assemblies such as signaling wands are used for directing automobile traffic and by ground crews at airports to direct and position aircrafts. Emergency services (e.g police and fire departments, military and coast guard, etc.) also use signaling wands and similar devices for managing crowds and signaling directives to coordinate activities.
Early signaling wands were crude adaptations of flash-lights that employed incandescent light-bulbs to illuminate a plastic tube-like structure. More recent signaling wands employ Light Emitting Diodes (LEDs) in place of incandescent light-bulbs. Examples include U.S. Pat. Nos. 5,079,679 (to Chin-Fa), 5,392,203 (to Harris, Jr.), 6,293,684 (to Riblett, E. L.) and 6,612,712 (to Nepil). Both incandescent light-bulbs and LEDs produce non-coherent light that is inherently limited in terms of both brightness and intensity.
By contrast, coherent light, as produced by lasers, is much more intense and bright than non-coherent light. However, unlike non-coherent light, coherent light from a laser does not radiate away from a source in a spherical fashion, but instead travels in a substantially straight path directly away from the source in a unidirectional beam. Direct exposure to coherent light is potentially dangerous to the human eye and consumer products employing laser-light sources are carefully regulated. Consequently, as a result of the radiation characteristics of coherent light, coherent light sources have not previously been employed for use in a signaling wand or any other direct-lighting apparatus.